Using the radioisotope scandium-46 to track the fate of seeds following removal by woylies (Bettongia penicillata) in an open wandoo (Eucalyptus wandoo) woodland in Western Australia

Murphy, M.T., Hardy, G. and Dell, B.
(2005)
Using the radioisotope scandium-46 to track the fate of seeds following removal by woylies (Bettongia penicillata) in an open wandoo (Eucalyptus wandoo) woodland in Western Australia.
In: 51st Scientific Meeting of the Australian Mammal Society, 4 - 8 July, Albany, Western Australia.

Abstract

Determining the consequences of animal-mediated seed dispersal for seedling recruitment is an important objective in understanding the dynamics of plant-animal interactions. However, tracking the fate of seeds following removal, from the source by an animal can be problematic, particularly for very small seeds. The aim of this study was to use a radioisotope, scandium-46, to label seeds and track their fate, using a Geiger counter, after they had been removed by woylies (Bettongia penicillata). A variety of seed sizes including sandalwood (Santalum spicatum) (n = 50), quandong (S. acuminatum) (n = 50), Acacia acuminata (n = 500), Allocasuarina huegeliana (n = 500) and Gastrolobium microcarpum (n = 500) were used. The large seeds were numbered with indelible ink and the small seeds were marked with white correction fluid. The seeds were soaked in a solution of distilled water and 37 MBq of scandium-46 until the water had absorbed into the seed coat. Experiments were carried out in an enclosure (220m x 85 m) in Dryandra Woodland, 165 km se of Perth Western Australia. Small seeds were placed on Petri dishes and large seeds scattered under sandalwood trees. There are six wild woylies in the enclosure and they have unlimited access to the seeds during the two week experiment. Because this experiment is in progress the results will be analysed at completion of the experiment in mid-May.